On Sat, May 22, 2004 at 09:47:59AM -0500, Marc Williams wrote: > On Sat, 2004-05-22 at 09:26, ne... wrote: > > On May 21, 2004 at 22:25, Marc Williams in a soothing rage wrote: > > > > >1) My IDE HDD spins down on a reboot. It's never done that with any > > >other distro that I've run on this machine. I don't think I like it. > > >Is this now normal? > > Yes, it seems so. > > > Rats. I would think that this behavior would put unnecessary stress on > the HDD. As far as placing unnecessary stress on the disk I would not give it a second thought. It is unlikely that you will be rebooting a large enough number of times that this matters at all. I expect your uptime will be measured in terms of weeks once you have the OS installed. 98% of all configuration changes do not require a reboot. In most cases a simple software command "service XYZ restart" is all you need after a change to a config file for it to be activated. <history> As far as the spin down and seek to the landing zone this is a desirable behavior for many disks. With the very low flying height of modern heads and that heads and media surfaces are very flat and 'stiction' is a common issue. Depending on the vendor and the drive minor amounts of stuff can build up on the heads and a drive that is halted and allowed to cool has a chance of sticking. A touch and go restart sequence tends to clean the surface of the heads and minimize (scrape off) this buildup of crud. About eight/ten years ago almost all the disk vendors had this problem with a new generation of media and heads and the microcode of the disks was enhanced to permit a touch and go cycle to minimize this as a problem. Since the internals of most disks are designed for the consumer market (media, heads, motors) the designs expect a power cycle a day or more because that is how people use them. It is also very common in places like Japan to turn off equipment for the night (plays havoc with cron jobs and system housekeeping). Some readers will correctly note that this stiction thing is OLD news but the key point is that historically all disk vendors suffer risks in this regard. A spin down land restart cycle is considered by some to be important in routine operation. There may be folks out there that design/support large RAID systems with racks of disks (100s). They may be able to comment about the importance of uninterruptible power and touch and go cycles with current devices. I know that in planning the physical move of of large disk farms that I have been involved in there was a step where the drives were conditioned (spun down/up) a number of times prior to power-off and letting them cool for the move. I have seen multiple disks fail in this conditioning cycles. Since the RAID was active it was simple to replace the drive and rebuild, no harm done. </history> -- T o m M i t c h e l l /dev/null the ultimate in secure storage.
